Electric furnace



June 30, w E MOQRE ELECTRIC FURNACE Original Filed Dec. 22, 1933 2 Sheets-Sheet,l

WMZMW E. Mware 2 Shets-Sheet 2 W. E. MOORE ELECTRIC FURNACE Original Filed Dec. 22, 1953 June 30, 1936.

Patented June 30, 1936 UNITED STATES ELECTRIC FURNACE William E. Moore, Pittsburgh, Pa., assignor to Pittsburgh Research Corporation, Pittsburgh,

Original application December 22, 1933, Serial 703,639. Divided and this application November 1, 1934, Serial No. 751,042

16 Claims.

My invention relates to improvements in electric furnaces and more particularly to furnaces of the type used in metallurgical operations.

.An important object of my invention is to provide novel electrode operating mechanism for electric metallurgical furnaces.

Another object of my invention is the provision of electrode operating mechanism especially adapted for use with tilting furnaces of the removable roof type.

A'further object of my invention is to provide a. novel winding drum for the electrode operating cables.

Other objects and advantages of my invention 15 will be apparent during the course of the following description. 1

The present'application is a division of my copending application serial No. 703,639 filed December 22, 1933. u

In the accompanyingdrawings which form a part of this specification, and wherein like characters of reference denote like parts throughout the same,

Figure 1 is an elevation of an electric metallur-- 25 gical furnace embodying my invention,

Figure 2 is a vertical sectional view of the electrode operating winch,

Figure 3 is a side elevation of the winch drum bushing, parts being broken away, and,

Figure 4 is an end elevation thereof.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral I0 designates the shell of a tilting electric metallurgical furnace having a removable roof I l. Tiltingof the furnace shell is effected by means of tilting mechanism l2. A spectacle casting I3 is detachably secured to roof II and is adapted to be engaged by a suitable lifting ram I4 for raising the spectacle casting and roof and swinging them away from, the furnace shell to permit charging of the furnace shell through its top. The construction of the furnace shell and roof, and the tilting and roof raising 45 mechanism is disclosed in my co-pending application above referred to and will not be described tacle casting l3 they are moved with the roof or rising structure when the roof is removed for charging the furnace.

It has heretofore been customary to mount the winches, for adjusting the electrode arms verticjally on the colunms, at a point spaced a sub- 5 stantial distance from the furnace, or directly upon the furnace shell. Either of these locations is disadvantageous with a removable roof or tilting furnace, because of the lift on the electrode arms when the. rising swing-aside structure is moved independently of the winches and I therefore propose to mount these winches upon some convenient place on the rising structure, as for instance the top of the electrode supporting columns as shown in Figure l. The electrode operl5 ating winches 20 may be of the usual motor driven construction such asshown in Figure 2 with metal winding drums 2| upon which the electrode operating cables 22 are wound. One end of each cable is attached to the cross head of one of the electrode armsll while the other end of each cable is attached to a counter-balance weight 23 arranged .to slide in the hollow columns l5. Spring buffers 24 are arranged on the bottoms of the electrode arms and in the lower position of the arms contact with the furnace roof or spectacle casting, allowing the cables 22 to slacken. In the upper position of the electrode arms the counter-balance weights 23 ground at the bottom of the columns and permit slackening of the cables.

The cables 22 are preferably ofsteel and if they are allowed to contact directly with the metal drums 2|, considerable wear on the drums and cables will result. In order to prevent this wear and at the same time permit rotation of the drumswithout a corresponding movement of the cables I provide a flexible sleeve 25 of fiber or other suitable material adapted to fit over each drum 2|. Each sleeve 25 is slit longitudinally at 26 as seen in Figures 3 and 4, and its inner surface is provided with a plurality of circumferentially, extending grooves 21 which terminate in radial openings 28 at points adjacent but spaced from the longitudinal slit 26. Rings or bands 29 of spring wire fit into the grooves 21 and have their ends arranged in openings 28. It will be seen that the spring wires 29 tend toexpand or open the split sleeve 25.

The sleeve 25 is dished inwardly slightly to conform to the shape of the drum 21 about which it is to be arranged. While the sleeves 25 may be formed in any suitable manner, they can be formed from a rectangular strip of fiber or other material properly grooved and then bent into a 55 generally cylindrical shape and set in this position.

In practice the split sleeve is arranged about the drum 2| as shown in Figure 2 and the electrode operating cable is wound about the sleeve and drum. Normally the weight of the counterbalances 23 and electrode arms H on cables 22 compresses the fiber bushings on drums it against the tension of springs 29 so that the sleeves will rotate with the drums to raise or lower the electrode arms. When the weights 23 ground at the bottom of columns IE or on suitable stops therein, or when the electrode arms contact with the roof or rising structure of the furnace through spring buffers 24, the weight on cables 22 is relieved, thereby allowing springs 29 to expand sleeves 25 and permit drums 2! to rotate within the split sleeves. Consequently limit switches to prevent stalling of the winch motors are not required.

As the entire electrode operating mechanism, including the Winches, is mounted upon the furnace roof or rising structure, it may be moved with the roof as a unit and will not interfere with movement of the furnace roof. The furnace may be tilted, or the furnace roof may beraised and moved away from the furnace shell without interference from the electrode operating mechanism.

In the claims, the terms furnace roof, removable furnace roof and roof" are used to designate the entire rising swing-aside structure including the furnace roof ring and the spectacle casting l3 which supports the electrode guide columns l5.

While I have shown and described the preferred embodiment of my invention, it is to be understood that various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention what I desire to claim and protect by Letters Patent is:

1,.An electric furnace comprising a furnace shell, a removable roof detachably secured thereto, hollow columns on said roof, electrode arms slidably supported on said columns, electric winches supported by said columns and having drums operated thereby, cables wound about said drums, each cable being secured at one end to an electrode arm and having its other end extending down into one of the columns, and a counterbalance weight slidably arranged within each column and secured to the cable extending into said column.

2. An electric furnace comprising a furnace shell, a removable roof detachably secured thereto, hollow columns on said roof, electrode arms movably supported on said columns, electric winches supported by said columns and having drums operated thereby, cables wound about said drums,-each of said cables being secured at one end to an electrode arm and having its other end extending down into one of the columns, a counterbalance weight slidably arranged within each column and secured to the cable extending into said column, and means operated by the weight of the electrode arms and counterbalance weights trode arms to raise and lower the arms on the columns, and means to disconnect the electrode arms and winches when the electrode arms reach their upper and lower limits of travel on the columns.

4. An electric furnace comprising a furnace shell, a roof secured thereto, columns on said roof, electrode arms slidably supported on said columns, winches supported by the columns and having winding drums, cables secured to the electrodearms and wound about said drums, whereby rotation of the drums will adjust the position of the electrode arms on the columns, and means interposed between the winding drums and cables to disconnect the drums and cables when the electrode arms are moved to their upper or lower limits of travel.

5. An electric furnace comprising a furnace shell, a roof secured thereto, columns on said roof, electrode arms slidably supported on said 20 columns, winches supported. by the furnace roof and having winding drums, sleeves arranged about said drums, and cables connected to said electrode arms and wound about said sleeves, whereby operation of said winches will adjust 25 the position of the electrode arms on the columns.

6. An electric furnace comprising a furnace shell, a roof secured thereto, columns on said roof, electrode arms slidably supported on the columns, electric winches supported by the roof 30 and having winding drums, split sleeves arranged about said drums, and cables secured to said electrode arms and wound about the split sleeves on the drums.

7. An electric furnace comprising a furnace shell, a roof secured thereto, columns on said roof, electrode arms slidably supported on said columns, electric winches supported by the columns and having winding drums, split sleeves surrounding said drums, resilient members arranged within said sleeves and tending to expand the same, and a cable wound about each sleeve and connected at one end to an electrode arm and at the other end to a counterbalance weight.

8. An electrode operating winch for electric furnaces comprising a winding drum, means to rotate said drum, a fiber sleeve surrounding the drum, and a cable wound about said sleeve and connected to an electrode to raise and lower the same.

9. An electrode operating winch for electric furnaces comprising a winding drum, means to rotate said drum, a split sleeve surrounding said drum, and a cable wound about said sleeve and connected to an electrode to raise and lower the same.

10. An electrode operating winch for electric furnaces comprising a winding drum, means to rotate said drum, a split sleeve surrounding the drum, a resilient member arranged within said 60 sleeve and tending to expand the same, and a cable wound about the sleeve and connected at one end to an electrode and at the other end to a counterbalance weight.

11. An electric furnace comprising a furnace 65 shell, a roof detachably secured thereto, means to raise the roof from the shell and swing it away from the shell, columns on the roof, electrode arms slidably supported on said columns, and electric winches mounted on said roof and oper- 70 atively connected to said electrode arms to raise and lower the arms on the columns.

12. An electric furnace comprising a furnace shell, a removable roof detachably secured thereto, columns on said roof, electrode arms slidably 75 supported on said columns, electric winches mounted on the roof and having rotatable drums, cables wound about said drums, each cable being secured at one end to anelectrode arm, counterbalance weights connected to the other ends umns and having rotatable drums arranged'in,

alignment with the open ends of the hollow columns, cables wound about said drums, each cable being secured at one end to an electrode arm and having its other end extending down into one of the columns, and a counterbalance weight arranged within each column and secured to the cable extending into the column.

14. An electric furnace comprising a furnace shell, a roof secured thereto, columns on said roof, electrode arms slidably supported on said columns, power winches supported by said columns and having rotatable drums, cables wound about said drums, each cable being secured at one end to an electrode arm, and counterbalance weights secured to the other ends of the cables and serving to counterbalance the weight of the electrode arms.

15. An electric furnace comprising a furnace shell, a removable roof detachably secured thereto. columnson said roof, electrode arms movably supported on said columns, power winches supported by the columns and having rotatable drums, cables wound about said drums, each of said cables being secured at one end to an electrode arm, counterbalance weights secured to the other ends of the cables and serving to counterbalance the weight of the electrode arms,

and means operated by the weight of the electrode arms and counterbalance weights to maintain the cables in operative engagement with the drums.

16. An electrode operating winch for electric furnaces comprising a winding drum, means to rotate said drum, a cable wound about said drum and connected at one end to an electrode to raise and lower the same and at its other end to a counterbalance weight, and means interposed between the drum and cable to disconnect the drum and cable when the electrode is moved to its upper or lower limit of travel.

WILLIAM E. MOORE. 

